21022002221 has 8 divisors (see below), whose sum is σ = 23421032064. Its totient is φ = 18704295520.

The previous prime is 21022002181. The next prime is 21022002271. The reversal of 21022002221 is 12220022012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21022002221 - 2²⁶ = 20954893357 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21022002196 and 21022002205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022002271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20330240 + ... + 20331273.

It is an arithmetic number, because the mean of its divisors is an integer number (2927629008).

Almost surely, 2^21022002221 is an apocalyptic number.

It is an amenable number.

21022002221 is a deficient number, since it is larger than the sum of its proper divisors (2399029843).

21022002221 is a wasteful number, since it uses less digits than its factorization.

21022002221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40661571.

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21022002221 its reverse (12220022012), we get a palindrome (33242024233).

The spelling of 21022002221 in words is "twenty-one billion, twenty-two million, two thousand, two hundred twenty-one".